This invention relates generally to non-metallic, spool fed line, grass trimmers and more particularly to a spool feed mechanism for such grass trimmers.
A variety of arrangements have been employed in prior art grass trimmers for feeding nylon or the like non-metallic line used for cutting vegatation, incrementally from a spool on which the line is stored. In these prior art arrangements, some type of mechanism is employed which releases the spool for rotation, causing an incremental feeding of the cutting line therefrom. Examples of such spool feed mechanisms are described in U.S. Pat. Nos. 4,118,864; 4,131,997; and 4,136,446.
In the case of the U.S. Pat. No. 4,118,864, a grass trimmer is disclosed wherein lengths of nylon or the like line are fed from two spools through the rotating drive shaft of an electric drive motor of the grass trimmer and out channels defined in the cutting head attached thereto. Centrifugal rotation of the cutting head and shaft pulls the line from two geared spools which cooperate with a worm pinion gear. Rotation of the assembly moves the pinion gear upwardly on a shaft. The release of a brake permits the pinion to travel back down the shaft, driving the geared spools to play out an increment of cutting line from each spool.
The U.S. Pat. No. 4,131,997 discloses a spool fed nylon cord grass trimmer employing rocker arms which cooperate with detents in the spool end to incrementally rotate the spool, thereby feeding out predetermined lengths of vegetation cutting line. The U.S. Pat. No. 4,136,446 shows an automatic, incremental line feed mechanism for a nylon line trimmer which employs an escapement mechanism cooperating with a radially ribbed spool to feed lengths of line therefrom.
In all of the arrangements of the last-mentioned art patents, the spool of line and release mechanism is carried on the cutting head of the grass trimmer. Release of the spool by operation of the release mechanism permits rotation of the spool relative to the trimmer head.
While the spool feed arrangements of the prior art operate satisfactorily for the most part to dispense incremental lengths of cutting line for cutting vegetation, changing of the spool necessitates either lifting the trimmer to a level whereat an operator can easily make the spool substitution or the operator must bend down to ground level to accomplish the latter. Furthermore, some mechanical connection or engagement with the feed mechanism must be made so that an operator can actuate the mechanism to feed lengths of cutting line therefrom during the operation of the trimmer without bending down to the trimmer head each time an additional length of cutting line is required.